1. Field of the Invention
This invention relates to an attendant console control system, and more particularly to an attendant console control system in which the key information input from an attendant console is transferred to a telephone exchange in a bit serial manner, and the line status information is periodically transferred from the telephone exchange to the attendant console in a bit serial manner so as to indicate the line status on the attendant console.
2. Description of the Prior Art
The operative state information of a telephone exchange is, in general, transferred to an attendant console for visual indication, as by lamps, and when a key operation takes place in the attendant console, the key information is transferred to the telephone exchange. It is desired to strictly limit such transferred information to only that which is necessary and sufficient so as to obtain an economical construction. With the improvement of performance and capability of exchange control equipment, exchange service becomes diversified. Since the exchange services is not fixed but differs with the user's requirements, it is desirable, from the standpoint of the operator, that the attendant console be easy to operate. With diversification of the exchange service, the amount of information to be transferred increases and the content of information differs with particular requirements. Accordingly, conventional systems are limited in flexibility, economy, ease of operation and maintenance.
FIG. 1 is a block diagram explanatory of the conventional system, in which subscribers' telephones 1a to 1n are connected to a network 3 through line circuits 2a to 2n, and the network 3 is connected to a distant office through a trunk 4. Attendant consoles 5a and 5b have connected to their display portions C-lines of the line circuits 2a to 2n. The key information by the key operation of the attendant consoles 5a and 5b is transferred to a common control equipment 8 through position controllers (pos. cont.) 7a and 7b, respectively, and the operative state information of the exchange is transferred from the common control equipment 8 to the attendant consoles 5a and 5b, also through the position controllers 7a and 7b, respectively.
The line status information in the attendant consoles 5a and 5b is displayed depending upon whether or not the C-lines of the line circuits 2a to 2n are grounded. With an increase in the number of C-lines connected to the display portion of the attendant console, the wiring becomes complicated and the construction of the system becomes very uneconomical. Further, in the case of changing the subscriber's telephone number, wiring modification and the like are required, and it is seen that the conventional system lacks flexibility.